Affinia Therapeutics Presents AFTX-201 Data and UPBEAT© Clinical Trial Design for BAG3-Associated Dilated Cardiomyopathy, Alongside Advances in BBB-Penetrant AAV Capsids and Proprietary Manufacturing, at the 29th ASGCT 2026 Annual Meeting

WALTHAM, Mass.--(BUSINESS WIRE)--Affinia Therapeutics (“Affinia”), an innovative clinical-stage gene therapy company with a pipeline of first-in-class and/or best-in-class adeno-associated virus (AAV) gene therapies initially for devastating cardiovascular diseases, today announced the presentation of new preclinical and translational data on the company’s lead program AFTX-201, the design of the Phase 1/2 UPBEAT^© clinical trial investigating AFTX-201 in patients with BAG3-associated dilated cardiomyopathy (DCM), Affinia’s blood-brain-barrier (BBB)-penetrant AAV capsids, and Affinia’s proprietary high-yield manufacturing process. This research was presented in several oral and poster sessions at the 29^th American Society of Gene & Cell Therapy (ASGCT) 2026 Annual Meeting, being held May 11-15, 2026 in Boston, MA, and virtually.

AFTX-201 is a potential best-in-class investigational genetic medicine for the treatment of BAG3-associated DCM. AFTX-201 is designed to deliver a fully human, full-length BAG3 transgene using Affinia’s proprietary capsid engineered for efficient cardiac transduction at doses that are 5-10-fold lower than those associated with gene therapies using conventional capsids such as AAV9 or AAVrh74. The UPBEAT clinical trial is investigating the safety and efficacy of AFTX-201 as a treatment for people living with BAG3 DCM. AFTX-201 is given as a simple one-time intravenous administration. AFTX-201 increased BAG3 protein levels in the heart and fully restored cardiac function in an animal model of BAG3 DCM.

The U.S. Food and Drug Administration has accepted Affinia’s Investigational New Drug application for AFTX-201 and granted it Fast Track designation during the first quarter of 2026. In addition, the European Medicines Agency has granted Orphan Drug designation to Affinia for AFTX-201 and the company recently received Clinical Trial Application approval from Health Canada to advance the UPBEAT clinical trial in Canada.

New AFTX-201 preclinical and translational data for BAG3 DCM featured at ASGCT 2026

New data show that in BAG3 haploinsufficient mice with established disease as demonstrated by cardiac functional deficit and structural abnormalities at baseline, a single intravenous (IV) dose of AFTX-201 at 9e11 vg/kg showed full correction of cardiac function and structure eight weeks post-dose. Pharmacokinetic assessments of AFTX-201 demonstrated durable transgene expression in the heart observed starting from 14 days post dosing up to 140 days post dosing in BAG3 haploinsufficient mice, which is the duration of the study and representative of the lifespan of the mice. Increase in AFTX-201 pharmacodynamics with durability of gene transfer and transgene expression up to six months post dosing were also observed in non-human primates (NHPs). Notably, the doses of AFTX-201 being advanced in the UPBEAT^© clinical trial caused gene transfer in the NHP cardiac tissue which was comparable in magnitude to levels seen with the efficacious dose of 9e11 vg/kg in BAG3 haploinsufficient mice. Toxicological assessments demonstrated that AFTX-201 is generally well tolerated, with no treatment-related mortality or significant adverse effects in mice or NHPs. Specifically, there were no elevations in liver function tests and no signs of complement activation in NHPs even without the use of prophylactic immunosuppressants. These preclinical studies provide support that the AFTX-201 doses in the UPBEAT clinical trial are safe and therapeutic. Additionally, in a head-to-head study, AFTX-201 at 9e11 vg/kg IV restored cardiac function in BAG3 haploinsufficient mice, while such an effect was not seen with a matched gene construct using the conventional capsid AAVrh74 at the same dose.

These data will be featured in an oral presentation entitled, “AFTX-201: A novel investigational AAV gene therapy for the treatment of BAG3-associated dilated cardiomyopathy,” being presented by Giri Murlidharan, Ph.D., Senior Director, Translational Biology at Affinia, today, Thursday, May 14, 2026, 3:45-4:00 pm ET (MCEC Room 206AB [Level 2]; abstract 381).

“AFTX-201 aims to be a transformative, one-time treatment to restore cardiac function and reverse heart failure in BAG3 DCM,” said Hideo Makimura, M.D., Ph.D., Chief Medical Officer at Affinia. “In preclinical studies, AFTX-201 has shown differentiated efficacy and improved safety as compared with a gene therapy construct using a conventional AAV capsid. The preclinical data presented at ASGCT support the safety and efficacy of the AFTX-201 doses being advanced into our first-in-human Phase 1/2 clinical trial (UPBEAT trial), using doses that are 5-10 times lower than those of investigational cardiac gene therapies employing traditional AAV capsids. We are delighted to announce advanced discussions with 10 potential trial sites across the U.S. and Canada for the UPBEAT trial, with the first site planned for Houston Methodist Hospital.”

“BAG3 DCM represents a significant unmet medical need as patients experience a rapidly progressive cardiac dysfunction and there is no treatment that exists which targets the underlying mechanism of disease,” said Arvind Bhimaraj, M.D., M.P.H., FACC, FHFSDA, Advanced Heart Failure Cardiologist and Physician Scientist, Houston Methodist Hospital. “AFTX-201 is designed to address the genetic root cause of BAG3 DCM and we look forward to participating in the UPBEAT clinical trial.”

Affinia’s Phase 1/2 UPBEAT^© clinical trial design for AFTX-201 in BAG3 DCM presented

Affina presented a poster at ASGCT 2026 about the design of its Phase 1/2 UPBEAT^© clinical trial (abstract 2363). The UPBEAT clinical trial is a multicenter, single-arm open-label Phase 1/2 clinical trial of AFTX-201 in adults with genetically confirmed BAG3-associated dilated cardiomyopathy. The trial includes a dose-exploration phase followed by a dose-expansion phase. All participants will receive a single intravenous infusion of AFTX-201 at a dose that has been deemed safe and efficacious based on preclinical studies. The primary objective of the trial is to evaluate safety and tolerability through 52 weeks following administration. Secondary and exploratory objectives include pharmacodynamic and preliminary efficacy assessments, which will be evaluated as changes from baseline. Multiple trial sites across the U.S. and Canada are planned to be available. Travel arrangements can be made for interested participants not living near a trial site. Interested participants who have a BAG3 mutation, are 18 – 55 years old, and have some difficulty performing normal physical activities, are encouraged to reach out via [e-mail]. The initial cohort of the trial is targeted to enroll three-to-five patients.

Affinia’s high-yield manufacturing process and analytical characterization of high-quality AFTX-201 clinical product highlighted

Affinia’s high-yield manufacturing process was featured in an oral presentation entitled, “Process development, technology transfer, clinical manufacturing, and process characterization of AFTX-201, an investigational new medicine for the treatment of BAG3-associated dilated cardiomyopathy,” presented by Matt Edwards, Vice President, Technical Operations, Affinia Therapeutics, yesterday (abstract 248).

Results presented showcased a robust and scalable, high-yield AAV manufacturing process that was successfully developed by Affinia and transferred to Forge Biologics for Good Manufacturing Practice (GMP) production of AFTX-201, supporting clinical development. Of note, the GMP run achieved exceptional harvest titers (> 6e15 vg/L) and quality attributes, exceeding typical industry benchmarks and providing confidence in being able to meet commercial demand of thousands of patients per year at a 50 – 250L scale after potential product approval.

In addition, the development, optimization, and qualification of a comprehensive product-specific analytical panel for AFTX-201 that demonstrates high-quality product in the UPBEAT^© clinical trial and also sets the foundation for the development of additional product candidates were featured in a poster entitled, “Development, technology transfer, and qualification of product-specific methods for AFTX-201, an investigational new medicine for the treatment of BAG3-associated dilated cardiomyopathy” (abstract 2215).

New data on Affinia’s blood-brain-barrier-penetrant capsid and on its myotropic capsid for Myotonic Dystrophy Type 1 presented

Progress in blood-brain-barrier (BBB)-penetrant capsid engineering was showcased in a poster entitled, “Engineered AAV Capsid Achieves Robust Transduction in Non-Human Primate Central Nervous System After Low Dose Systemic Administration” (abstract 2026). The data showed that the ATC-134 capsid using the H2B payload transduced >90% neurons across non-human primate (NHP) brain, including cortical, deep brain, and spinal cord regions at a dose of 3e13 vg/kg IV, enabling advancement to translational development at even lower doses for a number of neurological diseases.

Affinia’s myotropic and BBB-penetrant capsids are being advanced in multiple cardiac, skeletal muscle, and central nervous system indications. In a joint collaboration, Affinia’s myotropic capsid, ATC-187, was paired with Modalis Therapeutics’ epigenetic editing payload for a potential best-in-class gene therapy for Myotonic Dystrophy Type 1. Preclinical data were presented in a poster entitled, “Pairing AAV genome and capsid engineering of an epigenetic-editing modality to develop a best-in-class treatment for Myotonic Dystrophy Type1 (DM1)” (abstract 1492).

Affinia’s ASGCT presentations can be found on the company’s website at www.affiniatx.com/our-news/. Abstracts can be found at https://annualmeeting.asgct.org/.

About BAG3 DCM

BAG3 dilated cardiomyopathy (DCM) is a serious, inherited heart condition with a high mortality rate and a significant unmet medical need. The disease affects more than 70,000 patients in Canada and the E.U., U.K., and U.S. regions. The BAG3, or Bcl2-associated athanogene 3, gene encodes for a protein that is critical to the normal structure and function of heart cells. Patients with BAG3 DCM have a mutation in the BAG3 gene and a deficiency in functional BAG3 protein, resulting in early onset heart failure that progresses rapidly. Despite current standard of care, almost 25% of patients require a heart transplant.

About Affinia Therapeutics

Affinia Therapeutics is a clinical-stage biotech company pioneering a transformational treatment paradigm shift to a new class of rationally designed gene therapies that treat rare and prevalent diseases. Affinia Therapeutics’ pipeline of first-in-class or best-in-class product candidates, initially in cardiovascular diseases, leverages its proprietary next-generation capsids, payloads, or manufacturing approaches and have shown efficacy, safety, and differentiation in relevant animal models. For more information, visit https://www.affiniatx.com.